Procurement, Inspection, Storage, Usage, Polishing and Cleaning of Punches and Dies


 1.0 OBJECTIVE

  • To lay down a procedure for Procurement, Inspection, Storage, Usage, Polishing and Cleaning of Punches and Dies, which are used as tabletting tools.

2.0 RESPONSIBILITY

  • Technical Assistant – To follow the SOP.
  • Executive – To comply the SOP.

3.0 PROCEDURE

3.1 PROCUREMENT OF PUNCHES AND DIES:

  • Production department shall identify the required tabletting tool while reviewing the “DRAFT FOR REVIEW” copy of the particular Batch Processing Record of the particular product.
  • Based on the above requirement the production personnel shall coordinate with FRD for necessary approved design of punches used in the product development of the particular product.
  • Depending upon the approved drawing issued by FRD, the production department shall raise Design Specification (Annexure – 1) for the required sets of tabletting tool.
  • In design specification the production personnel shall give the detailed description of the Upper punches, Lower punches, Dies embossing details with required specifications and if any special recommendations for the supplier.
  • Finally the design specification shall be forwarded to Head – QA for authorization.
  • After the approval of the design specification by Head QA, the production personnel shall raise the indent for punches & dies, 35sets for Sejong 30stn. compression machine and 50sets for 45stn. compression machine.
  • The respective personnel along with the design specification shall approve the indent copy.
  • After the approval of indent copy, Purchase Order shall be raised along with the approved design specification.
  • Based on the above design specification the party shall submit the relevant Inspection Reports, MOC certificates, DQ’s, any aids like GO-NO-GO-Gauge etc.
  • The production personnel shall critically review after receiving the punches and dies, all relevant submitted data thoroughly against the established Approved Design.
  • If everything is satisfactory, the tabletting tools shall be subjected for inspection by production department and cross – checked by Engineering and QA deportment.
  • The inspection details shall be recorded as per Annexure – 2.
  • After completion of inspection, Head – Production, Engineering department and Quality assurance personnel shall critically review the inspection report against the approved design.
  • Any non confirming to the specification will be immediately returned to the suppliers for the replacement. Only inspected and good sets will be kept in change parts room in provided rack (production).
  • The unique no. shall be allotted as the following example:

             Ex: S-001-00

  • The first letter “S” indicates the Set Number.
  • The second letter is “dash”.
  • The next three digits indicate that sequential number of the set of the punches.
  • The last two digits indicate the No. of inspections carried.

3.2 Inspection Procedure

  • Use only the calibrated instruments for measuring the dimensions of the punches and dies.
  • Wipe off the oil from the surface with the lint free cloth and clean the punch and die sets to be inspected. Check all the punches and dies for any wear and tear or damaged surface.
  • Check the body diameter, punch length (overall and working), tip size, cup depth and concentricity for upper and lower punch, die diameter, height and bore.
  • Record the inspection of the punch and die as per the Annexure -2,3,4,5.

The following instruments are to be used to check the dimensions of various tooling as part of routine maintenance procedure:

  • Comparator.
  • Dial gauge.
  • Pointed brass anvil.
  • Ball anvil.
  • Length gauge.
  •  Appropriate punch holder (D Type).
  •  Vertically held V-block used in place of a punch holder.
  •  Micrometer.
  •  Die Bore GO-NO-GO gauge.
  •  Head GO-NO-GO gauge.
  •  Magnifying glass.
  • 3.3 SETTING UP THE COMPARATOR:
  • It is used to measure overall length, working length and tip to barrel concentricity of a punch. An optimal comparator with overlays also is used to check head profiles and overall length. The described steps for setting up the comparator should be followed carefully.

NOTE: The pointed brass anvil is used for punches with embossing or bisects lines and for punches with small tips and deep concavities. The ball anvil is used for flat and plain concave punches.

  • Place the length gauge on the comparator base under the dial indicator anvil while depressing the lifting lever.
  • Move the dial indicator unit on the pillar until it makes contact with the length gauge.
  • Continue to move the indicator until the pointer has made a sufficient revolution of dial to measure the appropriate depth of the punch concavity or barrel. Then send the indicator to zero.

NOTE: The number of revolution of the pointer will be shown on the small insect dial.

  • Remove the length gauge.
  • 3.4 PROCEDURE FOR MEASURING OVERALL LENGTH:
  • Place the punch in holder with tip in recessed end and head pointing up.
  • Place holder on base of comparator, depress lifting lever to raise anvil and slide punch and holder under the anvil.
  • Lower the anvil carefully on the head flap and record the indicator reading.
  • 3.5 PROCEDURE FOR MEASURING WORKING LENGTH:
  • Place punches in holder with head in recessed end and tip pointing up.
  • Place holder on base of the comparator depress lifting lever to raise anvil and slide punch and holder under the anvil.
  • Lower the anvil carefully on to the punch face and find the deepest point moving the punch and holder around until the dial indicator shows the minimum reading.
  • Subtract this minimum reading from the measured overall length and compare the difference to the theoretical or calculated cup depth. If the punch meets the standard, the difference in the length should closely approximate the cup depth.
  • The working length is the most critical punch dimension, because it controls tablet weight and thickness.
  • 3.6 PROCEDURE FOR MEASURING OF CUP DEPTH:
  • Obtain the theoretical depth of the cup from the tooling drawing or calculate the depth using for the formula for cup depths.
  • To find the actual cup depth, subtract the measured working length from the measured overall length.
  • Check the tolerance shown on tooling drawing or relevant tolerance charts to determine the diameter meets specification.  
  • 3.7 PROCEDURE FOR MEASURING TIP TO BARREL CONCENTRICITY:
  • Set up the comparator with a ball anvil and V – block.
  • Place V – block on comparator base, place punch in V block without side edge of the punch tip or tip straight under the indicator anvil to ensure sufficient register on the dial T.I.R.
  • Carefully rotate the punch and note pointer deflection, which should not exceed as per limits.

NOTE: Total indicator reading is the difference between the highest and lowest  readings taken during the rotation on the punch, eccentricity or deviation  from total indicator reading that exceed as per limits is excessive and could be caused by poorly manufactured tools.

  • 3.8 PROCEDURE FOR MEASURING PUNCH BARREL / BODY DIAMETER:
  • Measure barrel diameter with the micrometer.
  • Check the tolerance shown on tooling drawing or relevant tolerance charts, to determine if the diameter meets specification.
  • 3.9 PROCEDURE FOR MEASURING PUNCH TIP DIAMETER:
  • Measure the tip diameter with a micrometer.
  • Check the tolerance shown on tooling drawing or relevant tolerance charts to determine the diameter meets specification.
  • Using radius gauges that are thin steel templates and contain the range of internal and external criteria. Check the radius of punch faces, when the gauge is compared to the punch face there should be a good match of radius.
  • 3.10 PROCEDURE FOR CHECKING PUNCH HEAD AND NECK FACE
  • Using a go-no-go gauge check the punch head first by passing it through the go end, then check the head does not pass through the no go end.
  • Reject the punches not passing through the go end or that passes through no go end.
  • 3.11 PROCEDURE FOR INSPECTING PUNCH TIPS:
  • Use a magnifying glass to inspect the outside of the tip edges.
  • Check tip edges for raised burrs by visually inspecting the tip edge and / or by drawing a fingernail across the tip edge, be careful not to leave finger on the punch.
  • Visually inspect tip straight for scoring.
  • 3.12 PROCEDURE FOR INSPECTING THE PUNCH FACES:
  • Use a magnifying glass to inspect the punch faces for abrasion.
  • Visually inspect punch faces for corrosion.
  • 3.13 PROCEDURE FOR INSPECTING THE PUNCH HEADS:
  • Use magnifying glass.
  • Check under the head for irregular or excessive wear of the inside head angle.
  • Check the top of the head and head flat.
  • 3.14 PROCEDURE FOR DIE INSPECTION:
  • Die height is measured with micrometer. Alternative method is to use a comparator with a ball anvil on the dial indicator.
  • Die outer diameter is measured with micrometer.
  • Round die bores and shaped die bore are measured by passing the bore through go end of the appropriate GO-NO-GO. If the bore is correct size, the go end will pass through the bore whereas no go end will not.
  • 3.15 STORAGE OF PUNCHES:
  • Smear each punch and die with food grade oil (SYNTEL-H-1 grade) before replacing them back in respective boxes and store in the designated racks.
  • Inspection of the punches and dies shall be subjected for re-inspection after every 5 million tablets of compression of each set.
  • In case any deviation observed from the standard specification in the re-inspection, the respective punches shall be subjected for destruction with (As per Ref. SOP No.PR093) with prior approval from Head-Production.
  • The respective destruction details shall be recorded in the remarks column of the respective punch inspection report.
  • 3.16 USAGE OF PUNCHES AND DIES:
  • Technical Assistant should show all the required punches and dies to the Executive-Production before taking it for the compression of the batch.
  • Check all the punches and dies immediately after completion of the batch compression in presence of Executive-Production.
  • The sets shall be issued in a manner such that all the sets (actual qty. required for the machine +NLT 15% extra) on the rotational basis.

Ex :-     For a 30 station machine normally 35 sets are ordered. During routine usage only 30 sets shall be issued. On the 1st issuance set no.s 1 to 30 shall be issued, for the 2 nd 2 to 31, so on & so forth till Sl no.s 6 to 35, next issuance 7 to 1 up to 30 to 25. After sequence shall restart from Sl no.s 1 to 30 & continued in rotational manner.

  • Enter the details in the punch and die usage record as per Annexure-6.  
  • 3.17 POLISHING PROCEDURE OF PUNCHES AND DIES:
  • Use buffing machine for polishing of punch and dies.
  • RPM of the machine can be controlled for cleaning and polishing of punch tip and die-bore.
  • Procedure the following tools compounds before polishing.
  • Magnifying glass for identifying the damaged surface and finish of the tip.
  • Nylon brush, (cup type) with emery paste for cleaning and polishing of punch tip.
  • Oilstone and lapping stick for removing the burr or claw.
  • Felt bob, with emery paste for polishing embossed tips.
  • Emery paper or emery flour for removing corrosion from the tools.
  • Nylon brush (wheel type) for polishing embossed tips.
  • Silicon paste or emery flower for improving the surface finish. Finally polishing with diamond past for good surface finish.
  • 3.18 CLEANING PROCEDURE OF PUNCHES AND DIES AFTER POLISHING:
  • After polishing, mop the punches with lint free cloth.
  • Place the punches and dies in a cleaned tray separately.
  • Clean them with Iso Propyl Alcohol by using lint free cloth.
  • Apply Food grade oil in and outer surface of the punches and dies.
  • Keep them in the punch tray.
  • Put the Punch tray in the punch rack cabinet.
  • Clean the area thoroughly.
  • Clean the Polishing kit properly and keep it in its regular position.

NOTE: Punch polishing to be done after compression of 1 million tablets of each punch (Approximately).

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