X hits on this document

109 views

0 shares

0 downloads

0 comments

29 / 36

Cementing Plexiglas® Acrylic Sheet to Other Materials

Before specifying cementing for attachment of Plexiglas® acrylic sheet to dissimilar materials, the possibilities of mechanical attachment should be carefully evaluated. Properly designed mechanical attachment overcomes the difficulties often encountered with cementing. For some applications, pressure- sensitive, double-faced tape may be suitable for joining Plexiglas® acrylic sheet to other materials.

When it is necessary to cement Plexiglas® acrylic sheet to non-plastics, the dimensions of the cemented areas should be as small as possible. This is especially true if acrylic is cemented to materials that have much smaller coefficients of thermal expansion than Plexiglas® acrylic sheet does.

If it is unnecessary for the joint to be transparent, many adhesives, such as silicones, polysulfides, and rubber-based adhesives, are available. Most of these adhesives are suitable for outdoor applications.

Satisfactory joints between Plexiglas® acrylic sheet and other plastics and non-plastics are more difficult to make than Plexiglas® acrylic to Plexiglas® acrylic joints and usually give lower joint strength.

Table 5, below, gives a partial list of cements suitable for joining Plexiglas® acrylic sheet to other materials.

In most cases, there is a substantial difference in thermal expansion between Plexiglas® acrylic sheet and non-plastic materials. When joints between dissimilar materials are exposed to rising or falling temperatures, the materials expand and contract by different amounts, placing large stresses on any bond between them. Only cements that remain permanently flexible will continuously withstand these stresses.

Joining Plexiglas® Acrylic Sheet to Other Materials

PLEXIGLAS® Sheet Joined to:

Cement or Adhesive (4)

Remarks

Metal (1)

Contact cements, Polysulfide cements

Joint Life is limited. Maximum. bonding size is 2 ft. by 2 ft.; not suitable for outdoor use; joint is transparent; joint strength is low.

Rubber

PS-30, Weld-On 40 or 42

Before Plexiglas® acrylic sheet may be joined to rubber with cements that do not attack its surface, it is necessary to treat the rubber with sulfuric acid until the surface face hardens. The rubber is then washed and flexed, breaking the surface into cracks, which provide the means for mechanical adhesion of the cement to rubber.

Wood Vinyl (2)

PS-30, Weld-On 40 or 42

PS-30, Weld-On 40 or 42 Cyclohexanone

Suitable for outdoor use; joint is transparent.

Suitable for outdoor use; joint is transparent. Not suitable for outdoor use; joint is transparent.

ABS (3) Polycarbonate (3)

Polystyrene, Impact Styrene (3)

PS-30, Weld-On 40 or 42, Solvent PS-30, Weld-On 40 or 42, Solvent Solvent

Joint is transparent. Joint is transparent. Joint is transparent.

Styrene Acrylonitrile (SAN) (3)

PS-30, Weld-On 40 or 42, Solvent

Joint is transparent.

Cellulose Acetate Butyrate (CAB) (3)

PS-30, Weld-On 40 or 42, Solvent

Phenolics

TABLE 5

PS-30, Weld-On 40 or 42

  • (1)

    Thoroughly clean surfaces of metal with an organic solvent prior to joining.

  • (2)

    Avoid grades containing plasticizers that may migrate through the joint causing crazing of Plexiglas® acrylic sheet.

  • (3)

    These materials are not as durable as Plexiglas® acrylic sheet, when used outdoors.

  • (4)

    Consult the manufacturer or supplier for the appropriate MSDS for each adhesive or cement.

29

Document info
Document views109
Page views109
Page last viewedMon Dec 05 16:39:33 UTC 2016
Pages36
Paragraphs975
Words17780

Comments