Isikhwama esiphansi esiyisicaba siyindlela ethandwa kakhulu empilweni yansuku zonke.
I-OPP, i-PET, i-aluminium, ukwakheka kwe-PE. Izici zayo ziyi-compound fastness enhle kakhulu, amandla aphansi ezinyembezi, kulula ukudabula kuzo zombili izikhombisi-ndlela eziqondile nezivundlile ngemuva kokwenza isikhwama, izinga lokushisa eliphansi lokuvala uphawu, elifanele ukupakishwa okuzenzakalelayo kwesivinini esikhulu, ukugwema ukuphazanyiswa komoya-mpilo, i-ultraviolet nezinye izici.