Antioxidant, UV Stabilizer, Pigment, OBAs for Polyolefin 

Polyolefins are quantitatively the largest group of plastics. Depending on the starting materials (monomers) and the density (processing temperature), polyolefins may be classified according to the following principal groups:

  1. LDPE = Low-Density Polyethylene
  2. LLDPE = Linear Low-Density Polyethylene
  3. HDPE = High-Density Polyethylene
  4. PP = Polypropylene.

 

Antioxidant, UV Absorber And Light Stabilizer For Polyolefin

Hindered phenolic antioxidant 1010 is most frequently used in polyolefins’ processing. phosphite antioxidant 168 or thioester antioxidant DLTDP sometimes used with 1010 to achieve a synergetic effect. Benzophenone UV absorber 531, light stabilizer 622, 770 or HALS blends is used individually or together to protect polyolefins from photodegradation caused by light. The typical use of antioxidant and UV stabilizer additives for polyolefins as the table below.

Material Application Antioxidants UV Stabilizer Remark
PP thick section 260-280℃

Outdoor table & chair

1010+DSTDP 622+326 DSTDP=3*1010
PP thin section

Fiber & strip

240-300℃ PP fiber:1425

1010+168 DSTDP

 

Fiber:

770 without heat

622 with heat

Strip:791

Low volatile;

Heat stability;

Extraction resistance;

Gas yellowing

HDPE 180-240℃ blowing, injection, extrusion 1010+168 791 ,944 Compatibility
LDPE Film, packing, cover, mulch, greenhouse cover 1010 622+531 <0.1%
LLDPE Film, blowing, injection 1010+168 944 / 622+531 /
PEX Wire & cable TMB 6 / /
PB Pipe 1010DLTDP Extraction resistance

Optical Brightener For Polyolefin

Application OBAs Adding Form Typical OBAs Issue to mind
Polyolefin Dry powder mix FP 127

KSN

Compatibility

PP>hdpe>ldpe

Immigration resistance

 

Organic Pigment For Polyolefin (please click on title)

Things to know when selecting pigments for polyolefin

1. Distortion & Shrinkage 

A number of organic pigments cause distortion in certain types of polyolefins, especially in HDPE. These pigments also enhance the shrinkage of polyolefins, particularly in the direction of the flow.

2. Dispersibility 

The dispersibility of an organic pigment which is to be incorporated in a polyolefin is of particular importance. This is especially true for the coloration of extrusion films and for HDPE or PP ribbon made from stretched blown film or from sheeted extrusion film, as well as for the coating or melt spin dyeing. Powder form pigment dispersion is not adequate in these applications. Poor dispersion causes filler specks, holes in films, and other faults. Pigment preparations, usually in combination with polyolefins as a carrier, are frequently used to color polyolefins.

Pigment powders continue to be used in thick-walled articles, such as extruded sheets, or hollow objects, or in injection-molded products; although color concentrates are beginning to be more important even in these areas.

Pigment / polyolefin paste preparations containing between 20 and 70% pigment are also used. They are manufactured by means of three-roll mills, agitated ball mills, or dissolves or similar equipment. Such preparations are employed primarily to produce bottles, injection-molded articles, or extrusion sheets. These preparations have the advantage of being applicable in volumetric doses and may be premixed in slow mixers or gravitation mixers to uniformly adhere to the plastic granulate.