Rough Surface of Extruded Staioners' Rubber Bands

Manufacturer: We are manufacturing stationers' rubber bands using dry rubber extrusion process but have been experiencing undesirable surface roughness persistently. All attempts in reformulation and process changes are to no avail. Hope you can help us. We've sent you our formulations.

John Woon (Senior Latex Consultant): Thanks for sending me your formulations which helped me in my diagnosis of your problem.

You can easily overcome the problem by either switching your SMR to SP 20 or blending both.
SP means "Superior Processing Rubber" made form mixing vulcansied latex with normal latex at different ratios before the latex blend is coagulated to obtain the dry rubber. It has superior processing characteristics and good dimension stability which are ideal for calendering and extrusion processes. The extrudates would also show a smoother surface.

SP 20 indicates that 20% of the latex blend is vulcanised latex.

Poor Flocking Quality of Household Gloves

Manufacturer: We are household gloves manufacturers. We are struggling with the quality of our flocke-lined gloves due to poor flock pick-up.

John Woon (Senior Latex Consultant): Your latex formulation for the adhesive layer should be designed to ensure the latex does not flow excessively and also there is a good latex-pick up to receive the flocks and hence the addition of a thickener is necessary. Also your surfactant system much be designed to ensure that there is no premature gelation of the latex otherwise the adhesion of the flocks to the latex is poor.